Professor Alexander Orakhelashvili
Nature of the problem
The recent Chatham House document proposes certain criteria to “Identifying co-parties to armed conflict in international law”. The document focuses prevailingly on international humanitarian law (IHL) as part of jus in bello. It prioritises the notion of a “(co)party” to an armed conflict, upon attaining which status the relevant entity arguably operates in the legal framework applicable to armed conflicts. On what grounds does that happen and do those grounds have to do exclusively with IHL or jus in bello? Depending on what legal regimes would apply to such scenarios, we could speculate if, for instance, Germany delivered far-range missiles to Ukraine for the use of the latter’s war with Russia, whether Russia would be entitled to attack German military objects; or if France were to send its military personnel to Ukraine and if Russia captured some of them whether they would have to be released at any point when France would stop being involved in armed hostilities or whether the liberation of those captives would have to wait till the putative Franco-Ukrainian coalition would reach Moscow? Most importantly, are these issues to be determined on the basis that the relevant State is simply a “party” or “co-party” to the relevant conflict, so that little or nothing else would matter?
Most provisions of IHL cease to apply after active hostilities are over, but some of them continue applying even after hostilities. Depending on what is involved, thus, being a “party” could mean different things in different situations, e.g., “party” as a State of the nationality of prisoners of war who are held after the close of hostilities; and “party” who is entitled to target and take combat action against the adversary or can be lawfully attacked by the latter. No all-encompassing criteria are feasible because the range of the applicable legal framework could differ at various stages. At the even more basic level, and owing to specific provisions in applicable treaties, whether the legal regime governing armed conflicts continues to apply after active hostilities have ceased is an issue different from whether and when that armed conflict has genuinely started, and thereby peaceful relations between the relevant States have been replaced by an armed conflict. Any feasible guidance on this matter has to be sought in the requirements of the legal system, not in any abstract concepts (or cluster-concepts).
The Chatham House document suggests that the “co-party” status turns on “an objective assessment of the relevant facts” (p.20). That requirement could get compromised, given that the document contains a rather presumptive statement that “[n]either treaty law nor customary international law explicitly provides criteria for determining co-party status”. And “[t]herefore, rules must be drawn from the legal framework of international law in armed conflict and in light of state practice in past and current conflicts. The task in establishing criteria is thus to draw out what international treaty and customary rules presuppose, when they refer to parties to a conflict, about what has made the respective collective entity a party.” (p.9, emphasis added). The thesis that “International law presupposes” certain things without establishing clear rules on the relevant matters (p.9) is rather problematic in both methodological and evidentiary senses and conveys an impression of the adherence to the natural law thinking. The above problem is then corroborated by a somewhat dismissive attitude towards jus ad bellum. The document goes on to suggest that jus ad bellum standards are “contested and unsettled” and not particularly helpful to discern when States become “co-parties” to an armed conflict (pp.15-16). As I pointed out earlier, this attitude is too dismissive towards jus ad bellum and portrays jus in bello or IHL as the legal framework of near-exclusive relevance; if that position was part of positive international law, it would only increase legal protection for States who engage in illegal and aggressive uses of force.
The essence of being a “co-party” to an armed conflict
One of the premises adopted in the Chatham House document is that, somewhat open-endedly or circularly, “the relationship between multiple co-parties must be such as to warrant treating them as parties to the same armed conflict.” Apparently, the conduct of various entities ought to be tied together and produce a legal status of a “co-party” (p.19). The problem is corroborated by the document’s choice to take a “one size fits all” approach towards various armed conflicts in which the legality of State involvement has to be measured by diverse criteria, and the standard of ascertaining the extent of State responsibility with regard to assisting other States or NSAs could also be different. The document suggests that “[s]tructurally, both the requirement of resort to armed force in IAC and protracted armed violence in NIAC regard the nature of the conflict as a whole.” Hence, the relevant “criteria must be met overall by all co-parties in their confrontation with the adverse side” (p.12), rather than by each relevant entity. The proposition suggested requires, thus, that there is a single criterion applicable to various of conflicts and the involvement of various types of entities (whether State or non-State). This assertion or proposition puts the cart before the horse, because the “overall” conflict is not something whose existence or scale could, in the legal sense, be taken for granted. Instead, any armed conflict is created through the requisite conduct of States or other qualified entities. Care ought thus to be taken not to assume that a certain “whole” could exist or be projected a priori, or that its scale exceeds or is generically different from the cumulative extent of actual military confrontation between various entities, or that any armed conflict could inherently and legally exist on some meta-bilateral plane.
The document suggests that some discrete, disparate or interrelated activities of States “effectively build on one another” and create the status of a “co-party” to an armed conflict (p.19). While it is true that diverse actions could “build on one another” and produce a certain form of social reality, that “building” process would not necessarily produce the desired legal result unless the elements of that possess the required legal qualification. In a purely socio-political sense, assistance that Ukraine receives from multiple countries does build on its capacity to fight the defensive war and visibly transforms the underlying socio-political reality. However, what also matters is the assessment of the nature of activity of every State on its own, because only this way could we identify whether an internationally wrongful act or other action classified by international law in a certain way is being carried out. In this area as in many others, the law addresses and bestows certain qualification on the conduct of individual entities.
The Chatham House document states regarding international armed conflicts (IAC) that “on a widespread view, there is no intensity threshold for an IAC to exist or, [it is] at most, a low one”, and “resort to armed force [suffices to generate] an IAC”. Given, therefore, that the threshold is so low and relatively easy to meet, whether any two States are at an armed conflict with a third State could be ascertained without separately addressing the conduct of each of those two States (pp.11-12, 17). But what happens if, for instance, State A has illegally used force against State B but no actual military confrontation between A and B has ensued, and the State C has similarly used force against State B or did something that reinforces State A’s capacity to further or more efficiently use force against State B? There would be no armed conflict to speak of. The document’s assertions go too far by envisaging scenarios in which a State would be a party to an armed conflict deemed to be ongoing between two other States not only even if that State is not actually involved in a military confrontation with any other State, but also even if the two or more other States are or were not involved in such military confrontation when some other State is portrayed to have intervened in and become a “co-party” to that projected armed conflict. While such situations could witness one or more acts of aggression, they would hardly witness a situation of an armed conflict unless, and additionally, two or more States’ armed forces are also engaged in an ongoing mutual armed confrontation.
That the notion of “co-party” is too terse and generalised is also obvious as both the initiation and conduct of various types of armed conflicts are governed different sets of international legal rules. Regarding State intervention in an internal armed conflict between rebels and a government, some illegal action by that State has to be involved, qualifying at least as an unlawful interference in the territorial State’s internal affairs, for instance by aiding rebels, or as an illegal use of force against the territorial State, for instance by fomenting rebellion or organising armed activities on the transnational plane. An external State intervention on the side of the territorial State government and against rebels is lawful if based on the consent of the latter government. Moving to international armed conflicts, initially we deal with a range of economic, financial, security or military cooperation between States which are, as such, lawful activities. But they could be unlawful if they support a State in its aggressive war or in committing violations of international humanitarian law. This would generate the assisting State’s responsibility for the relevant aggression or violations of IHL; but this still would not qualify the assisting State as a party to any armed conflict unless its organs or armed forces get involved in an actual military confrontation with another State’s organs or armed forces.
The Chatham House document relies on a rather broad formulation (contained in Tadic, para 70) that the applicability of IHL begins as of the initial resort to force and lasts until a general peace is concluded (presumably a peace agreement rather than a merely factual cessation of hostilities). On facts of the case, however, the Tribunal was more nuanced and observed that “There has been protracted, large-scale violence between the armed forces of different States” to which IHL has applied. The ICTY’s above initial formulation was too broad and hardly related to facts of the case. The resort to an armed force may be a necessary condition for an IAC to be created but it is hardly a sufficient condition for that. What would be legal or practical implications of IHL in the absence of a visible or sustained armed confrontation between armed forces two States? There would be no facts Geneva Conventions or their Protocols to apply to and hence no legal consequences arising under IHL. In the absence of an actual military confrontation with another State, a State is unlikely either to comply with or violate requirements arising under international humanitarian law, either by targeting or treatment of war prisoners, or of civilians. It also bears repeating that it has to be a real armed conflict for IHL to apply, not an artificially presupposed or constructed one to give protection to the aggressor.
Modes of involvement
The Chatham House document also admits that the existence of a “co-party” status in an armed conflict also requires “a direct connection to hostilities” and “some degree of cooperation or coordination with at least one other co-party” (p.17, emphasis original). Hostilities are described as “the means and methods of causing harm to the adversary” and as “the most granular components of the conflict relationship between adverse parties” (p.19). Also, the document is generally ridden with the use of relative terms such as “some degree”, “sufficient link”, or “exact degree”. This conveys the impression that there is no transparent criterion, and conclusions may depend on facts more than on anything else. But against what standard or criterion should those facts be assessed unless hostilities are about the actual military confrontation of organs or armed forces of one State against those of another State and, as the document contends by relying on little more than academic writings, hostilities are about more than attacks (and by implication defensive operations) in the sense of Article 49 API 1977 (p.18)? It is hardly a sustainable criterion that there are hostilities when facts suggest that there are hostilities. And while both the document, with its diverse hypothetical or open-ended examples, and another commentator (p.187) seem to agree that the standard ought not to be set “too low” and that an armed conflict or use of force should not be identified with mere aid and assistance provided to one of the belligerents, still the Chatham House document speaks of several practical instances of what on their face come across as mere aid or assistance, and fails to come up with any transparent alternative criterion to demonstrate what the required higher threshold may be. In is not clear, moreover, what that higher threshold could be short of a State’s direct involvement in hostilities. There could hardly be any tertium genus between being and not being involved in fighting. Attempts to introduce newer notions such as “co-party” relate to the range of activities which evade any uniform characterisation through the application of any of international law’s existing concepts, and they risk encompassing the position of accomplices and belligerents alike.
In some places, the Chatham House document tries to get more specific by suggesting that “if military advisers of one state assist in the planning of specific military operations by another state, to the point that both states are involved in the decision-making process for specific operations in the conduct of hostilities, there can be both a sufficiently direct connection to hostilities and a sufficient degree of cooperation and coordination.” (p.21) Apart from the words “to the point” exposing the (recurrent) open-endedness and circularity, the criterion of close connection to hostilities is still too broad, because mere aid or assistance could also be closely connected to hostilities. Speaking of relations between a State and a non-State actor, the ICC has mentioned the element of “participation in the planning and supervision of military operations” (Ntaganda, para. 727), presumably in the sense that the intervening State’s activities directly account for relevant combat activities that conceivably also include violations of IHL. The intervening State is thus in a position to prevent the occurrence of violations of IHL. On this account, State responsibility for those violations would be based on causation. Also, for this reason, giving specific orders to commit those violations may not be a necessary precondition for responsibility. On facts of the case, the Court specified (at para.730) that the “overall control” test which according to it embodies the above requirements was not met. The Court took the same approach towards Ugandan and Rwandan activities in Katanga (paras 1213-1214). As a corollary to those findings, the degree of outside State intervention did not rise to the level of aggressive use of force that would make the intervening State a party to an international armed conflict (see for further detail here).
Proximity and time elements are important considerations on the State-to-State plane, but they do not necessarily foreclose the recipient State’s ability to decide how to use the assistance, information, tools or expertise provided. If requirements stated in relation to aid and assistance (in ILC’s Article 16 ASR and commentary to it, emphasising causation) are taken on their face value (see further here and here), the assisting State becomes responsible for the recipient State’s conduct through the use of the aid and assistance provided when the relevant ultimate steps and activities are no longer the product of the recipient State’s autonomous and separate activity (though the knowledge of the recipient State’s past conduct contrary to international law could in certain cases compensate for the prospective uncertainty about that conduct that could exist in other cases and thus make the causal connection easier to identify). But all that operates on the plane of secondary norms to assess the extent of the assisting State’s responsibility for an act of aggression or violations of IHL, as opposed to turning that State into a “co-party” to an armed conflict and subjecting it to rights and obligations arising under IHL. Some activities that might seem to amount to mere aid and assistance, such as making State territory available for troops transportation, overflight, or weapons delivery, could involve an obvious connection to the overall violation of jus ad bellum, and hence qualify as pure aggression rather than aid or assistance in its perpetration (as would also follow from Article 3(f) of GA Resolution 3314 incidentally, if not curiously, being the only provision of that Resolution that the Chatham House document expressly mentions). In other areas of law such as IHL, connection to specific acts of hostility would have to be demonstrated and the enabling element has to be tied to the performance of specific operations and activities so that, in essence, they are not simply a product of the recipient State’s autonomous and separate activities. If that is the case, the aiding or assisting State will be responsible for consequent violations of IHL by the recipient. But that is not the same as participation in an armed conflict. In other words, it is not about whether weapons are delivered “virtually onto the battlefield” as Schaller puts it (p.189), or very close in advance to the fighting. It is not about the locus, but about the authorship of the combat activities.
The Chatham House document mentions that the US has viewed Kuwait and Qatar 2003 as co-party to its armed conflict with Iraq because they had provided their territory to the US (pp.11-12). However, on that account alone a State could be co-aggressor but not necessarily a “co-party”. The document goes on that “when a state allows its territory to be used as a launchpad for specific hostilities against another state or armed group, this may constitute a sufficient connection to the hostilities” (p.22). This is put on rather jus ad bellum-blind terms, and it is unclear anyway how could a State engage in hostilities against another State without using force against it first (which would be an aggressive use of force unless the requirements of collective self-defence would be met, on which see below). A State involvement in IAC has to be preceded either by its use of force in violation of jus ad bellum or its exercise of the right to self-defence; but not every violation of jus ad bellum will by itself generate an IAC or turn the aggressor State into a “co-party”.
“Indirect force”, again
As some form of the use of force directly attributable to the intervening State has to be involved before an international armed conflict materialises, the “indirect use of force” thesis initially raised by Schmitt & Biggerstaff also needs to be addressed, in terms of what legal differential it could possibly add to the existing calculus of rights and obligations of States. In a more recent paper, admitting that this is a somewhat relative criterion, Christian Schaller suggests that a contribution that reaches the level of crossing the threshold of a use of force could be categorised as a form of indirect use of force; and “to reach the level of an indirect use of force coming within the scope of Article 2(4) of the UN Charter, a contribution must be made to another state’s direct use of force” (Schaller 185, 188, emphasis original). Precisely this creates a normative and analytical problem because, if an act amounts to “indirect force”, then it is a type of “use of force” that does not as such make any legal difference unless it is connected to another and more “direct” type of the use of force, and hence such act should make no legal difference.
Schaller is rather open in suggesting that, “From the benchmark of Article 16 ASR, an appropriate higher standard for the concept of indirect use of force could be deduced” (Schaller, 189). Were that the case, a secondary norm of responsibility would guide us towards understanding the scope of a primary rule of conduct as to what amounts to aggressive war, or what counts as an involvement in an armed conflict. Moreover, whether all aspects of Article 16 provide generally accepted benchmarks is questionable, as the ILC’s criteria and commentary on this matter are not very consistent. But the ILC is clear on the core issue that complicity is about contribution, enhancement of capacity, enabling something to happen, and leading to the assisting State’s responsibility for the final harmful outcome. All that is different from a direct perpetration of the prohibited act or conduct. What is on occasions described as “indirect force” could typically be one State’s participation in another State’s wrongful act, but not use of force as such or violation of IHL. There is no requirement, under jus ad bellum or jus in bello, to reclassify such conduct, unless some specific rule requires that, for instance Article 3(f) on definition of aggression under GA Resolution 3314, regarding allowing the use of State territory for perpetrating acts of aggression against another State. In relation to non-State actors, GA Resolution 2625 qualifies instigation or fomenting use of force, acts of terrorism or civil strife by one State in the territory of another State as a direct use of force: not a complicity or assistance of any form but a direct authorship of the use of force. Either way, thus, “indirect force” is neither here nor there.
Collective self-defence
Jus ad bellum determines when the initial threshold of becoming a party to an international armed conflict is crossed. This could happen through an unlawful invasion of a State or other forms of aggression towards it, or through a lawful use of force consisting of collective self-defence. This latter option would be the only legally allowed route for any State to join the Ukraine-Russia armed conflict on the side of Ukraine. In such case, Ukraine would be inviting another State’s armed forces not simply to operate in its territory but also to act against armed forces of a third State (Russia). Collective self-defence is thus different from mere intervention by consent: a mere placement of third State military personnel in Ukraine is (or most of the time) a matter between Ukraine and the sending States; using the same personnel as part of hostilities the way that would matter in terms of the IHL criteria of targeting and combatancy would become a matter between the sending State(s) and Russia.
Third State participation in this armed conflict cannot be validated or legitimised on any other ground. As the International Court has emphasised in Nicaragua (pp.44-45, 119-121), “the normal purpose of an invocation of self-defence is to justify conduct which would otherwise be wrongful.” Assisting Ukraine short of direct involvement in hostilities is hardly wrongful. Therefore, an invocation of collective self-defence would be bound to amount to a major admission of the intervening or assisting State’s involvement in hostilities against Russia. The Court in Nicaragua was clear that for collective self-defence to be activated, one State (let’s say Ukraine) must declare itself a victim of armed attack and invite other State(s) to joint its defensive war. As this cannot be done through the backdoor, by implication or stealth, because ICJ’s criteria are formulated in terms of public awareness and clarity, this would inevitably involve the assumption of heavy political and legal responsibility and would not be something that could be done clandestinely or contextually and then be denied at every convenient occasion. This is the only route through which those other States could fight lawfully on Ukraine’s side. For, even if Russia has committed aggression against Ukraine, third States are not entitled to undertake forcible countermeasures (which are unlawful in all circumstances) against Russia when requirements of collective self-defence are not fulfilled. In that latter case, the intervening third States would be committing an act of aggression against Russia by attacking the latter’s forces or territory.
Schaller has suggested (pp.197-198) that “no in-depth discussion is needed to show that the conditions of collective self-defence would be fulfilled (with the exception of the formal reporting requirement contained in Article 51 of the UN Charter)”, because Western assistance given to Ukraine have “an explicitly articulated intent to force Russia to back off.” The mere intent, however far-reaching, does not turn aid and assistance into a use of force. However, if certain forms of what is initially portrayed as assistance were to go as far as amounting in the assisting State’s involvement in hostilities against Russia, then the “assisting” or intervening States would incur all consequences of an aggressive use of force, because their action would not have gone through the collective self-defence process as described above. If they would opt for a sustained military confrontation with Russia, they would become a party to an international armed conflict but also risk losing privileges ordinarily available to belligerents (see for detail here, here, and here). It should be pointed out also that the Chatham House document (p.26) is also inconclusive on the aggressor discrimination issue, because it does not rule out that the aggressor State could still benefit from safeguards available under jus in bello.
Conclusion
A State cannot become a party or “co-party” to any armed conflict by implication, stealth or through the backdoor, and without initially using force against some other State. This is the initial condition precedent. Unless (collective) self-defence requirements are met, any use of force is bound to be illegal. The proper way of doing this regarding Ukraine-Russia conflict is that Ukraine would extend a request or invitation to relevant Western State(s) to join in collective self-defence and get involved in an armed confrontation with Russia; the latter States would then have to accept that request or invitation and get involved in hostilities accordingly. This would obviously require serious political decisions, public discussion, and a major political consensus at national and transnational levels. While Western political leaders have already discussed or debated some potential measures that could amount to their intervention in the ongoing Ukraine-Russia conflict, what the current academic debate should not do is to second-guess the outcome of the above political debate or pre-empt political decisions or circumvent the lack of them. On the methodological plane, IHL is not a set of nice labels allowing to think away much of everything else; it can have no self-contained effect in this area and such effect cannot be feasibly imitated by the portrayal of a cluster-notion of a “co-party”. Criteria supporting this notion in the Chatham House document are often open-ended and mostly rely on academic writings. The most important challenge to the viability to this proposed cluster-notion is that becoming a “co-party” is impossible without significant legal and political cost and responsibility of relevant States, and several aspects of this are overlooked in that document.